[77 280z th350 driveshaft length]

 unless you never go over 60 mph run from that 350th thats what I have

[New build and New here]

 best money you can spend buy a copy of Jags that can run Datsun Z V-8 conversion manuel by Mike Knell it will save thousand in hours and money

[Transmission options? Currently TH350]

 I currently have the same problem but I am considering the weaker 200 because of the electonics on the 700r4 what would I be facing with the 700r4?

[280Z with TH350, stock 280Z shifter setup?]

The reason it doesnt cover the TH350 is it is not a recommended tranny. I have one in my 260z and it is wound tight at highway speeds.

[The dreaded "diff" CLUNK]

thank you for explaining why I found the front of my diff strapped down with 1/4" cable it actually works

[hawaiian with questions]

Congrats on your buy. These cars are great.I'll only speak about what I know stay away from the TH350 and TH400 your overall gear ratio is way too low. I have a TH350 and it sounds way too tight at 70 MPH. 2nd thing buy this book it is expensive but you will use it all the time you have your Z http://www.jagsthatrun.com/Pages/Datsun_Z_V-8.html